Method of making torsion springs



Aug. 5, 1941. G. H. PARKER METHOD Q Original Filed Max-6h 1. 1.959

F MAKING TORSION SPRINGS [N VEIVTOR Patented Aug. 5, 1941 METHOD OF MAKING TORSION SPRINGS a1 Oak, Mlch., assignor to Glenn H. Parker, Roy Chrysler Qorporation,

corporation of Delaware Highland Park, Mich., :1.

Original application March 1, 1935i, Serial No. 259,202. Divided and this application October 26, 1939, Serial No. 301,480

ll Claim.

This invention relates to torsion springs of the type embodying non-metallic bodies such as rubber composition or other suitable plastic material and is a division of my copending application Serial No. 259,202, filed March 1, 1939.

"My invention is especially adapted for use in conjunction with ground wheels of motor vehicles, the torsion springs preferablyserving to yieldingly support the vehicle structure on the ground wheels. In such arrangements the torsion springs may be arranged to accommodate spring of the ground Wheels independently of each other. My improved torsion spring may also be used to advantage in a wide variety of other uses wherever it is desired to connect two members for torsional control of their relative movement.

it is an object of my invention to provide an improved method of making a torsional spring whereby the cost of the assembly is minimized and the life of the spring increased.

Another object is to provide a torsional spring oi improved strength and wherein improved resistance to failure is afforded.

While the torsion spring assembly may comprise a rubber body frictionally or mechanically connected to the relatively movable members of the oscillatory joint, I preferably provide for bonding the rubber or other plastic material to the joint members during the usual vulcanizing and. curing of the rubber so that a unit is formed of the rubber and the metallic members bonded thereto.

One feature of my invention comprises an improved method of forming the spring with concentric metallic structures between which the rubber body is located, one of the structures being discontinuous for the purpose of placing the rubber under radial compressive stress to increase its life and improve its torsional action. ihis discontinuous structure, as a feature of my invention, serves as a connecting support for the spring without requiring additional enclosing structures for attaching the spring to one of the relatively oscillatory members.

Another feature of my invention resides in a method of forming a discontinuous or segmental sleeve for the rubber body, the rubber being radially protruded at the gap between the sleeve segments and bonded thereto to reduce the stress in the rubber at this critical region.

Further objects and advantages of my invention will be apparent from the following description of one illustrative embodiment thereof, reference being bad to the accompanying drawing in which:

Fig. 1 is a side elevational view somewhat diagrammatically showing my invention applied to a vehicle wheel suspension.

Fig. 2 is an enlarged side elevational view showing my torsion spring as viewed in Fig. 1.

Fig. 3 is a sectional elevational view of the torsion spring taken as indicated by line t-3 of Fig.2.

Fig. l is a sectional view of a portion of the torsion spring illustrating the method'of molding the same.

- Fig. 5 is a similar view illustrating the spring after cooling from the molding process.

Referring to the drawing 1 have illustrated my invention in the form of a torsion spring unit or assembly A for yieldingly mounting the vehicle frame structure B on the front ground wheel C.

The wheel mounting may be of any suitable type such, for example, as illustrated in the copending application of Woolson et al., Serial No, 238,421, filed November 2, 1938. With such arrangement, the wheel is carried by a crank arm ill and is additionally stabilized by the cooperating parallelogram system comprising the system of pivotal links ii, it. As the wheel rises and falls, the torsion spring A yieldingly resists suchmovemerit and, by its torsion action, supports the frame on the wheel C by reason of the wheel carrying arm it.

The spring It has inner and outer structures'or parts, one of which is'securely attached to arm it and the other of which is secured to frame B. By preference, an inner structure comprising a metallic cylindrical sleeve or hollow shaft it is continuous and is bonded to the annular rubber body it. This body is externally embraced by an enclosing structure comprising a discontinu ous cylindrical sleeve formed of segments it, it preferably two in number such that each is a berm-cylinder likewise bonded to the body it...

Each of the segments it, it has a pair of diametrically opposite outwardly extending clamp-.

ing lugs or, abutment flanges ill, it respectively, serving as means to draw the segments together to compress the rubber body it and also to at tach the spring un't to the frame B. For this purpose each pair of companion flanges ll, it has a pair of aligned openings it, ill for receiving a fastener assembly 211.

i'he spring is vulcanized as shown in Fig. 4, the segments l5, it being eccentrically spaced by removable filler blocks 22 between each pair of flanges ll, it such that after the unit is removed from the mold (not shown) and the blocks 22 reto receive the segment I8 and transfer the vermoved. the. shrinkage of the rubber will bring tical loads between the wheel and frame. The

e segments toward each other to the member has flanges 28 abutting flanges I1 condition to relieve the rubber of tension stress each of the pairs of fasteners 2I serving to clam while still preserving a gap 23 etween e 5 gether one set of the flanges 26 I1 and I8 anges When the unit is assembled by fasteners For additional rigidity one or both segments may 2|, gap is closed thereby placing the rubber be rib In e rawings I have illustrated under initial radial compressive stress segment I 6 as formed with t e reverse-bent rib As shown in Fig 4, the blocks 22 do not entire] 9 extending around the segment body and conconrorm with, or complete the approximately 10 tinuing to the flanges I8 between the associated cylindrical surface represented at 24 interiorly pairs of fasteners 2!. of segments I5, I6; On the other hand, the blocks I do not limit my invention, in the broader a radial rubber rib 25 will be formed bonded to described for illustrative purposes since various ture be ween flanges I1 I and the main bod ings of my invention and scope thereof as defined portions of the segments I5 I6. The ribs do the appended cl not project so far as to prevent the flanges from a I claim is be clamped together as in Fig. 2 but the ar- 20 The method of making a torsion bearing which the body I4 and also form the outer supporting outwardly therefrom to said spacers, removing l7, II. In practice, for a wheel suspension, the the material, and mounting the assembly with the frame B is preferably provided with a fabricated flanges of the segments clamped together to hold hollow welded cross brace 26 having a bottom the plastic body under radial compressive stress. hemi-cylindrical member 21 thereof which serves GLENN H. PARKER. 

